Adhesion pathway proteins and risk of atrial fibrillation in the Multi-Ethnic Study of Atherosclerosis.

BACKGROUND: The cellular adhesion pathway has been suggested as playing an important role in the pathogenesis of atrial fibrillation (AF). However, prior studies that have investigated the role of adhesion pathway proteins in risk of AF have been limited in the number of proteins that were studied and in the ethnic and racial diversity of the study population. Therefore we aimed to study the associations of fifteen adhesion pathway proteins with incident AF in a large, diverse population. METHODS: Multi-Ethnic Study of Atherosclerosis participants from four races/ethnicities (n = 2504) with protein levels measured were followed for incident AF (n = 253). HGF protein was measured on Exam 1 samples (N = 6669; AF n = 851). Cox proportional hazards regression was used to assess the association of AF with 15 adhesion pathway proteins. Bonferroni correction was applied to account for multiple comparisons. RESULTS: After adjusting for potential confounding variables (age, sex, race/ethnicity, height, body mass index, systolic blood pressure, antihypertension therapy, diabetes status, current smoker, current alcohol use, and total and HDL cholesterol), and accounting for multiple testing (P < 0.05/15 = 0.0033), circulating levels of the following proteins were positively associated with a higher risk of AF: MMP-2 (HR per standard deviation increment, 1.27; 95% CI 1.11‒1.45), TIMP-2 (HR 1.28; 95% CI 1.12‒1.46), VCAM-1 (HR 1.32; 95% CI 1.16‒1.50), and SLPI (HR 1.22; 95% CI 1.07‒1.38). The association between proteins and AF did not differ by race/ethnicity. CONCLUSIONS: Circulating levels of MMP-2, TIMP-2, VCAM-1, and SLPI were positively associated with an increased risk of incident AF in a diverse population. Our findings suggest that adhesion pathway proteins may be important risk predictors of AF.

Increased hepatocyte growth factor levels over 2 years are associated with coronary heart disease: the Multi-Ethnic Study of Atherosclerosis (MESA)

Hepatocyte growth factor (HGF) is associated with subclinical and clinical atherosclerosis. However, the significance of change in HGF and development of atherosclerotic disease is unknown. In a large and diverse population-based cohort, we report that change in the biomarker HGF is an independent predictor of incident CHD.

Hepatocyte growth factor is associated with progression of atherosclerosis: The Multi-Ethnic Study of Atherosclerosis (MESA).

BACKGROUND AND AIMS: Hepatocyte growth factor (HGF) has previously been associated with risk of stroke, coronary heart disease, and atherosclerosis. We hypothesized that higher circulating HGF is associated with greater progression of measures of atherosclerosis: coronary artery calcium (CAC) and carotid plaque. METHODS: Participants aged 45-84 years from the prospective cohort study Multi-Ethnic Study of Atherosclerosis had HGF measured at baseline (between 2000 and 2002) and were followed for progression of atherosclerosis for up to 12 years. CAC was measured at all five exams using the Agatston method. Mixed-effects models were used to examine the association of HGF and CAC progression among 6695 participants with available data. Relative risk regression was used to assess the association between HGF and new or additional carotid plaque between exams 1 and 5 in 3400 participants with available data. All point estimates were adjusted for potential confounding variables. RESULTS: Each standard deviation higher HGF at baseline was associated with 2.9 Agatston units/year greater CAC progression (95% CI: 1.6-4.2, p < 0.0001), and the magnitude of this association differed by race/ethnicity (p value for interaction by race = 0.003). Each standard deviation higher HGF at baseline was associated with a 4% higher risk of new or additional carotid plaque (95% CI: 1.01-1.08, p = 0.005). CONCLUSIONS: Higher levels of HGF were significantly associated with greater progression of atherosclerosis in this large and diverse population. Circulating HGF continues to show promise as a potential clinical biomarker for cardiovascular disease.

Low high-density lipoprotein cholesterol and particle concentrations are associated with greater levels of endothelial activation markers in Multi-Ethnic Study of Atherosclerosis participants.

BACKGROUND: High-density lipoproteins (HDL) are well characterized for their role in reverse cholesterol transport but may confer other cardiovascular benefits-specifically, HDL may suppress the endothelial activation cascade in the initiating stages of atherogenesis. OBJECTIVE: It was the primary aim of this study to examine the relations of HDL cholesterol (HDL-C), total HDL particle (HDL-P) concentrations, and HDL-P subclasses with circulating levels of endothelial activation markers in a subcohort of Multi-Ethnic Study of Atherosclerosis participants. METHODS: HDL-C was measured by enzymatic assay, and total HDL-P and subclass concentrations were assessed by nuclear magnetic resonance spectroscopy. Concentrations of circulating endothelial activation markers were determined through immunoassay. Multivariable linear regression was used to determine the cross-sectional associations between HDL variables and endothelial markers with statistical adjustment for age, race/ethnicity, sex, education, systolic blood pressure, hypertension medication use, body mass index, smoking status, lipid-lowering medication use, serum creatinine, diabetes, low-density lipoprotein cholesterol, and coronary artery calcium. RESULTS: HDL-C and HDL-P were found to be inversely associated with soluble vascular cell adhesion molecule-1, soluble vascular intracellular adhesion molecule-1, sL-selectin, and sP-selectin; HDL-P was additionally inversely associated with sE-selectin. Participants with low levels of HDL-C (<40 mg/dL) or HDL-P (<25th percentile) showed 3%-12% higher mean levels of soluble vascular cell adhesion molecule and compared with those above these levels (all P < .01). CONCLUSION: Coupled with previous evidence, our findings suggest a modest to moderate relation of HDL and circulating levels of endothelial activation markers in humans. Whether this relationship may have clinical implications in suppressing atherogenesis or coronary heart disease development requires additional research.

Hepatocyte growth factor demonstrates racial heterogeneity as a biomarker for coronary heart disease.

OBJECTIVE: To determine if hepatocyte growth factor (HGF), a promising biomarker of coronary heart disease (CHD) given its release into circulation in response to endothelial damage, is associated with subclinical and clinical CHD in a racial/ethnic diverse population. METHODS: HGF was measured in 6738 participants of the Multi-Ethnic Study of Atherosclerosis (MESA). Highest mean HGF values (pg/mL) were observed in Hispanic, followed by African, non-Hispanic white, then Chinese Americans. RESULTS: In all races/ethnicities, HGF levels were associated with older age, higher systolic blood pressure (SBP) and body mass index, lower high-density lipoprotein, diabetes and current smoking. In fully adjusted models, each SD higher HGF was associated with an average increase in coronary artery calcium (CAC) of 55 Agatston units for non-Hispanic whites (p<0.001) and 51 Agatston units for African-Americans (p=0.007) but was not in the other race/ethnic groups (interaction p=0.02). There were 529 incident CHD events, and CHD risk was 41% higher in African (p<0.001), 17% in non-Hispanic white (p=0.026) and Chinese (p=0.36), and 6% in Hispanic Americans (p=0.56) per SD increase in HGF. CONCLUSION: In a large and diverse population-based cohort, we report that HGF is associated with subclinical and incident CHD. We demonstrate evidence of racial/ethnic heterogeneity within these associations, as the results are most compelling in African-Americans and non-Hispanic white Americans. We provide evidence that HGF is a biomarker of atherosclerotic disease that is independent of traditional risk factors.

ABO blood group is associated with peripheral arterial disease in African Americans: The Multi-Ethnic Study of Atherosclerosis (MESA).

INTRODUCTION: Peripheral artery disease (PAD) affects 8.5 million Americans and thus improving our understanding of PAD is critical to developing strategies to reduce disease burden. The objective of the study was to determine the association of ABO blood type with ankle brachial index (ABI) as well as prevalent and incident PAD in a multi-ethnic cohort. METHODS: The Multi-Ethnic Study of Atherosclerosis includes non-Hispanic White, African, Hispanic, and Chinese Americans aged 45-84. ABO blood type was estimated using ABO genotypes in 6027 participants who had ABI assessed at the baseline exam. Associations with ABO blood type were evaluated categorically and under an additive genetic model by number of major ABO alleles. After excluding those with ABI>1.4, prevalent PAD was defined as ABI≤0.9 at baseline and incident PAD as ABI≤0.9 for 5137 participants eligible for analysis. RESULTS: There were 222 prevalent cases and 239 incident cases of PAD. In African Americans, each additional copy of the A allele was associated with a 0.02 lower baseline ABI (p=0.006). Each copy of the A allele also corresponded to 1.57-fold greater odds of prevalent PAD (95% CI, 1.17-2.35; p=0.004), but was not associated with incident PAD. No associations were found in other racial/ethnic groups for ABI, prevalent PAD, or incident PAD across all races/ethnicities. CONCLUSIONS: Blood type A and the A allele count were significantly associated with baseline ABI and prevalent PAD in African Americans. Further research is needed to confirm and study the mechanisms of this association in African Americans.

Elevated Levels of Adhesion Proteins Are Associated With Low Ankle-Brachial Index.

Inflammation plays a pivotal role in peripheral artery disease (PAD). Cellular adhesion proteins mediate the interaction of leukocytes with endothelial cells during inflammation. To determine the association of cellular adhesion molecules with ankle-brachial index (ABI) and ABI category (≤1.0 vs >1.0) in a diverse population, 15 adhesion proteins were measured in the Multi-Ethnic Study of Atherosclerosis (MESA). To assess multivariable associations of each protein with ABI and ABI category, linear and logistic regression was used, respectively. Among 2364 participants, 23 presented with poorly compressible arteries (ABI > 1.4) and were excluded and 261 had ABI ≤ 1.0. Adjusting for traditional risk factors, elevated levels of soluble P-selectin, hepatocyte growth factor, and secretory leukocyte protease inhibitor were associated with lower ABI ( P = .0004, .001, and .002, respectively). Per each standard deviation of protein, we found 26%, 20%, and 19% greater odds of lower ABI category ( P = .001, .01, and .02, respectively). Further investigation into the adhesion pathway may shed new light on biological mechanisms implicated in PAD.

Hepatocyte Growth Factor Is Positively Associated With Risk of Stroke: The MESA (Multi-Ethnic Study of Atherosclerosis).

BACKGROUND AND PURPOSE: Hepatocyte growth factor (HGF) is positively associated with ischemic and hemorrhagic stroke risk factors. However, understanding the relation between HGF and stroke is in its infancy. Therefore, we sought to examine the association of circulating HGF with incident stroke using data from the MESA (Multi-Ethnic Study of Atherosclerosis). We hypothesized that circulating HGF would be positively associated with an increased risk of stroke. METHODS: Participants aged 45 to 84 years (n=6711) had HGF measured between 2000 and 2002 and were followed for incident stroke through 2013 (n=233). Cox proportional hazards regression was used to calculate hazard ratios and 95% confidence intervals for incident stroke. A secondary analysis stratified results by adjudicated stroke type (n=183 ischemic; n=39 hemorrhagic; n=11 other). RESULTS: After adjustment for potential confounding variables, risk of stroke was 17% higher with each standard deviation increase in HGF (hazard ratio, 1.17; 95% confidence interval, 1.03-1.34). This association was mainly driven by ischemic stroke and did not change on exclusion of cardioembolic strokes, although the number of excluded cases was small. The few hemorrhagic and other types of stroke were not associated with HGF. CONCLUSIONS: Circulating HGF was positively associated with the incidence of stroke in a diverse, population-based cohort of men and women from the United States. Our findings support the hypothesis that circulating HGF is a marker of endothelial damage and suggest that HGF may have utility as a prognostic marker of stroke risk.

ABO blood group associations with markers of endothelial dysfunction in the Multi-Ethnic Study of Atherosclerosis.

BACKGROUND AND AIMS: ABO blood type is associated with cardiovascular disease, although the underlying mechanisms are presumed to be complex. While the relationship between non-O blood types and von Willebrand Factor (vWF) is well-established, associations with cellular adhesion molecules (CAMs) across diverse populations are understudied. METHODS: We genetically inferred ABO alleles for N = 6202 participants from the Multi-Ethnic Study of Atherosclerosis. Linear regression was used to evaluate associations between major ABO allele dosages and log-transformed measurements of vWF (N = 924), soluble E-selectin (sE-selectin, N = 925), soluble P-selectin (sP-selectin, N = 2392), and soluble ICAM-1 (sICAM-1, N = 2236) by race/ethnicity. RESULTS: For the selectins, the A1 allele was associated with significantly lower levels for all races/ethnicities, with each additional allele resulting in a 28-39% decrease in sE-selectin and 10-18% decrease in sP-selectin relative to Type O subjects. However, the A2 allele demonstrated effect heterogeneity across race/ethnicity for sE-selectin, with lower levels for non-Hispanic whites (p = 0.0011) but higher levels for Hispanics (p = 0.0021). We also identified elevated sP-selectin levels for B-allele carriers solely in Hispanic participants (p = 1.0E-04). ABO-by-race/ethnicity interactions were significant for both selectins (p < 0.0125). More modest associations were observed between A1 allele dosage and levels of sICAM-1, with ABO alleles explaining 0.8-1.1% of the total phenotypic variation within race/ethnicity. ABO associations with vWF activity were consistent across race/ethnicity, with B allele carriers corresponding to the highest vWF activity levels. CONCLUSIONS: ABO blood type demonstrates complex associations with endothelial markers that are largely generalizable across diverse populations.

Blood group antigen loci demonstrate multivariate genetic associations with circulating cellular adhesion protein levels in the Multi-Ethnic Study of Atherosclerosis.

The cellular adhesion pathway is critical in the pathophysiology of atherosclerosis, and genetic factors contributing to regulation of circulating levels of related proteins may be relevant to risk prediction of cardiovascular disease. In contrast to conducting separate genome-wide protein quantitative trait loci (pQTL) mapping analyses of each individual protein, joint genetic association analyses of multiple quantitative traits can leverage cross-trait co-variation and identify simultaneous regulatory effects on protein levels across the pathway. We conducted a multi-pQTL (mpQTL) analysis of 15 proteins related to cellular adhesion assayed on 2313 participants from the Multi-Ethnic Study of Atherosclerosis (MESA). We applied the MQFAM multivariate association analysis method in PLINK on normalized protein level residuals derived from univariate linear regression, adjusting for age, sex, and principal components of ancestry. Race/ethnicity-stratified analyses identified nine genome-wide significant (P < 5e-08) loci associated with co-variation of protein levels. Although the majority of these SNPs were in proximity to structural genes of the assayed proteins, we discovered multiple loci demonstrating co-association with the circulation of at least two proteins. Of these, two significant loci specific to non-Hispanic white participants, rs17074898 at ALOX5AP (P = 1.78E-08) and rs7521237 at KIAA1614 (P = 2.2E-08), would not have met statistical significance using univariate analyses. Moreover, common patterns of multi-protein associations were discovered at the ABO locus across race/ethnicity. These results indicate the biological relevance of blood group antigens on regulation of circulating cellular adhesion pathway proteins while also demonstrating race/ethnicity-specific co-regulatory effects.

Circulating level of hepatocyte growth factor predicts incidence of type 2 diabetes mellitus: The Multi-Ethnic Study of Atherosclerosis (MESA).

BACKGROUND: Hepatocyte growth factor (HGF) is a pleotropic factor posited to have metabolic homeostatic properties. The purpose of this study is to examine whether level of HGF is associated with the development of type 2 diabetes. METHODS: Data from the Multi-Ethnic Study of Atherosclerosis (MESA) were used to examine the prospective association between serum level of HGF and incident diabetes. Fasting HGF was measured at Exam 1 (2000-2002) in 5395 participants free from diabetes (61.5±10.2 years old) and incidence of diabetes was determined at four subsequent follow-up exams over 12 years. Hazard ratios (HR) for incident diabetes were estimated according to 1 standard deviation (SD) unit increment of HGF (1 SD=26 µg/l), before and after adjustment for age, sex, race/ethnicity, education, study center, smoking status, alcohol consumption, body mass index, waist circumference, fasting glucose and insulin, C-reactive protein, and interleukin-6 levels. RESULTS: A 1 SD increment of baseline HGF was associated with a 46% (95% CI=1.37, 1.56) increased risk of diabetes before adjustment. After adjustment, diabetes risk per 1 SD increment of HGF was attenuated but remained significantly increased (HR=1.21; 95% CI=1.12, 1.32). Men had a significantly greater HR compared to women per equivalent increase of HGF (p-value for sex interaction=0.04). There was no evidence of effect modification by race/ethnicity. CONCLUSIONS: This study advances understanding from cross-sectional studies and investigation of incident insulin resistance, demonstrating higher level of HGF is associated with incident diabetes and may reflect a unique type of impaired metabolism.

Impact of adiposity on cellular adhesion: The Multi-Ethnic Study of atherosclerosis (MESA).

OBJECTIVE: At the cellular level, how excess adiposity promotes atherogenesis is not fully understood. One pathway involves secretion of adipokines that stimulate endothelial dysfunction through increased expression of adhesion molecules. However, the relationship of adiposity to adhesion molecules that promote atherosclerosis is largely unknown. METHODS: Linear regression models were used to assess the sex-specific associations of soluble cellular adhesion molecules (sP- and sL-selectin, sICAM-1, sVCAM-1, and sHGF) and adiposity in 5,974 adults examined as part of the Multi-Ethnic Study of Atherosclerosis (MESA). Adiposity measures included body mass index (BMI), waist-to-hip-ratio (WHR), and computed tomography measures of subcutaneous adipose tissue (SAT) and visceral adipose tissue (VAT). RESULTS: The mean age was 64 years and 52% were female. In multivariable models adjusting for traditional cardiovascular risk factors, sHGF was positively associated with BMI, WHR, and VAT in both males and females, and sP-selectin with WHR and VAT in males. sVCAM-1 was inversely associated with VAT in females only. CONCLUSIONS: Our results showed the relation of adiposity to soluble cellular adhesion proteins was similar across adiposity measures and for both sexes. However, the relationship between adiposity and sVCAM-1 and P-selectin may be modified by sex and the measure used to assess adiposity.

A microfluidic multiplex proteomic immunoassay device for translational research.

OBJECTIVE: Microfluidic technology has the potential to miniaturize and automate complex laboratory procedures. The objective of this study was to assess a microfluidic immunoassay device, Simple Plex, which simultaneously measured IL-1ß, TNF-α, IL-6, and IL-10 in serum samples. This assessment is important to understanding the potentials of this microfluidic device as a valuable tool in translational research efforts. METHODS: We studied the operational characteristics of Simple Plex, and compared to other immunoassay systems including bead-based (i.e., Bio-Plex(®) from Bio-Rad) and planar micro-spot based (i.e., Multi-Array from Meso Scale Discovery) multiplex assays. We determined imprecisions for each of the Simple Plex assays and evaluated the ability of Simple Plex to detect IL-1ß, TNF-α, IL-6, and IL-10 in serum samples. RESULTS: Simple Plex assays required 25 µL serum, and 1.5 h to run 16 samples per cartridge per instrument. Assay imprecisions, evaluated by measurement of 6 replicates in duplicate from a serum pool using three different cartridges, were less than 10 % for all 4 cytokine protein biomarkers, comparable to the imprecisions of traditional ELISAs. The Simple Plex assays were able to detect 32, 95, 97, and 100 % [i.e., percentages of the results within the respective analytical measurement ranges (AMRs)] of IL-1ß, TNF-α, IL-6, and IL-10, respectively, in 66 serum samples. CONCLUSIONS: Simple Plex is a microfluidic multiplex immunoassay device that offers miniaturized, and automated analysis of protein biomarkers. Microfluidic devices such as Simple Plex represent a promising platform to be used in translational research to measure protein biomarkers in real clinical samples.

Trans-ethnic meta-analysis identifies common and rare variants associated with hepatocyte growth factor levels in the Multi-Ethnic Study of Atherosclerosis (MESA).

Hepatocyte growth factor (HGF) is a mesenchyme-derived pleiotropic factor that regulates cell growth, motility, mitogenesis, and morphogenesis in a variety of cells, and increased serum levels of HGF have been linked to a number of clinical and subclinical cardiovascular disease phenotypes. However, little is currently known regarding which genetic factors influence HGF levels, despite evidence of substantial genetic contributions to HGF variation. Based upon ethnicity-stratified single-variant association analysis and trans-ethnic meta-analysis of 6201 participants of the Multi-Ethnic Study of Atherosclerosis (MESA), we discovered five statistically significant common and low-frequency variants: HGF missense polymorphism rs5745687 (p.E299K) as well as four variants (rs16844364, rs4690098, rs114303452, rs3748034) within or in proximity to HGFAC. We also identified two significant ethnicity-specific gene-level associations (A1BG in African Americans; FASN in Chinese Americans) based upon low-frequency/rare variants, while meta-analysis of gene-level results identified a significant association for HGFAC. However, identified single-variant associations explained modest proportions of the total trait variation and were not significantly associated with coronary artery calcium or coronary heart disease. Our findings indicate that genetic factors influencing circulating HGF levels may be complex and ethnically diverse.

P-selectin and subclinical and clinical atherosclerosis: the Multi-Ethnic Study of Atherosclerosis (MESA).

OBJECTIVE: P-selectin is a cellular adhesion molecule that has been shown to be crucial in development of coronary heart disease (CHD). We sought to determine the role of P-selectin on the risk of atherosclerosis in a large multi-ethnic population. METHODS: Data from the Multi-Ethnic Study of Atherosclerosis (MESA), including 1628 African, 702 Chinese, 2393 non-Hispanic white, and 1302 Hispanic Americans, were used to investigate the association of plasma P-selectin with CHD risk factors, coronary artery calcium (CAC), intima-media thickness, and CHD. Regression models were used to investigate the association between P-selectin and risk factors, Tobit model for CAC, and Cox regression for CHD events. RESULTS: Mean levels of P-selectin differed by ethnicity and were higher in men (P<0.001). For all ethnic groups, P-selectin was positively associated with measures of adiposity, blood pressure, current smoking, LDL, and triglycerides and inversely with HDL. A significant ethnic interaction was observed for the association of P-selectin and prevalent diabetes; however, P-selectin was positively associated with HbA1c in all groups. Higher P-selectin levels were associated with greater prevalence of CAC. Over 10.1 years of follow-up, there were 335 incident CHD events. There was a positive linear association between P-selectin levels and rate of incident CHD after adjustment for traditional risk factors. However, association was only significant in non-Hispanic white Americans (HR: 1.81, 95% CI 1.07 to 3.07, P=0.027). CONCLUSION: We observed ethnic heterogeneity in the association of P-selectin and risk of CHD.

Soluble P-selectin predicts lower extremity peripheral artery disease incidence and change in the ankle brachial index: the Multi-Ethnic Study of Atherosclerosis (MESA).

OBJECTIVE: To determine the association of circulating P-selectin with prevalent and incident peripheral artery disease (PAD), the ankle brachial index (ABI), and change in the ABI. METHODS: The Multi-Ethnic Study of Atherosclerosis (MESA) is a prospective population-based cohort study including 6814 European descent, African American, Hispanic and Chinese men and women aged 45-84 at baseline. Four clinical exams took place after the baseline exam. After excluding those with ABI>1.4, prevalent and incident PAD were defined as an ABI≤0.90. ABI progression was defined as progression from a normal ABI (0.91-1.4) to abnormal (≤0.90 or >1.4) at a later exam. RESULTS: In adjusted models, each SD (13 ng/mL) higher P-selectin was significantly associated with 0.007 lower ABI (95% CI ((-0.011, -0.004)), p < 0.001), and an average change in the ABI of -0.006 ((-0.010, -0.003, p < 0.001). P-selectin was significantly associated with a 1.17-fold greater odds of prevalent PAD ((1.02, 1.33), p = 0.03), and a 30% greater risk of incident PAD ((1.11, 1.53), p = 0.001), as well as progression from a normal ABI to an ABI≤ 0.90 (p = 0.003), but not to an ABI>1.4 (p = 0.96). Addition of P-selectin to models containing traditional PAD risk factors and markers of inflammation/coagulation significantly improved the net reclassification for ABI progression (p = 0.03), but was only marginally significant for incident PAD (p = 0.06). CONCLUSIONS: P-selectin is significantly associated with the development of PAD. However, further research is needed in population-based studies to confirm prospective associations of P-selectin with incident PAD and change in the ABI, as well as its potential predictive ability.

Multi-ethnic analysis reveals soluble L-selectin may be post-transcriptionally regulated by 3'UTR polymorphism: the Multi-Ethnic Study of Atherosclerosis (MESA).

L-Selectin is constitutively expressed on leukocytes and mediates their interaction with endothelial cells during inflammation. Previous studies on the association of soluble L-selectin (sL-selectin) with cardiovascular disease (CVD) are inconsistent. Genetic variants associated with sL-selectin levels may be a better surrogate of levels over a lifetime. We explored the association of genetic variants and sL-selectin levels in a race/ethnicity stratified random sample of 2,403 participants in the Multi-Ethnic Study of Atherosclerosis (MESA). Through a genome-wide analysis with additive linear regression models, we found that rs12938 on the SELL gene accounted for a significant portion of the protein level variance across all four races/ethnicities. To evaluate potential additional associations, elastic net models were used for variants located in the SELL/SELP/SELE genetic region and an additional two SNPs, rs3917768 and rs4987361, were associated with sL-selectin levels in African Americans. These variants accounted for a portion of protein variance that ranged from 4 % in Hispanic to 14 % in African Americans. To investigate the relationship of these variants with CVD, 6,317 subjects were used. No significant association was found between any of the identified SNPs and carotid intima-media thickness or presence of carotid plaque using linear and logistic regression, respectively. Similarly no significant results were found for coronary artery calcium or coronary heart disease events. In conclusion, we found that variants within the SELL gene are associated with sL-selectin levels. Despite accounting for a significant portion of the protein level variance, none of the variants was associated with clinical or subclinical CVD.

Repeated versus single measurement of plasma omega-3 fatty acids and risk of heart failure.

PURPOSE: Studies have previously examined the relation between a single measure of plasma fatty acids and risk of heart failure. However, it is unclear whether the use of repeated measures of fatty acids over time is required for the assessment of omega-3 fatty acids heart failure relation. METHODS: Using a nested case-control design, this ancillary study used 421 cases and 421 matched controls from the Physicians' Health Study to assess the variability of plasma phospholipid fatty acids over time and compare the results of omega-3 fatty acids heart failure associations using a single versus repeated measurements of plasma phospholipid fatty acids. Plasma omega-3 fatty acids were measured at baseline (1982) and approximately 15 years later using gas chromatography. RESULTS: Spearman's correlation coefficients between baseline and follow-up measures of α-linolenic acid (ALA), EPA, DPA, and DHA were 0.20, 0.45, 0.28, and 0.50, respectively, in the control series. Multivariable adjusted odds ratios for heart failure per standard deviation higher plasma ALA were 0.98 (95% CI 0.85-1.13) when using baseline ALA and 0.86 (95% CI 0.74-1.01) when using the average of baseline and follow-up ALA measurements. Corresponding odds ratios for total long chain omega-3 FAs (EPA + DHA + DPA) were 0.87 (0.73-1.03) and 0.88 (0.75-1.04). CONCLUSIONS: Our data demonstrate modest correlation between measurements of plasma phospholipid fatty acids spaced by 15 years. A single measurement of plasma phospholipid fatty acids appears reasonable to estimate the risk of heart failure over long-term follow-up.

Plasma cis-vaccenic acid and risk of heart failure with antecedent coronary heart disease in male physicians.

BACKGROUND & AIMS: Although an inverse association of red blood cell cis-vaccenic acid and risk of myocardial infarction has been reported, it is unclear whether cis-vaccenic acid might lower the risk of heart failure (HF) with antecedent coronary heart disease (CHD). We sought to examine the relation of plasma cis-vaccenic acid with HF with antecedent CHD. METHODS: This nested case-control study was based on 788 incident HF cases (of whom 258 cases had antecedent CHD) and 788 controls. Each control was selected using a risk set sampling technique at the time of the occurrence of the index case and matched on year of birth, age at blood collection, and race. Fatty acids were measured using gas chromatography and incident HF was self-reported on annual questionnaires and validation in a subsample using medical records. RESULTS: In a multivariable conditional logistic regression, the odds ratio (95% confidence interval) for HF with prior CHD were 1.0 (ref), 0.72 (0.33-1.57), 0.28 (0.12-0.67), and 0.23 (0.09-0.58) across consecutive quartiles of cis-vaccenic acid (p_trend 0.0004). Each standard deviation of cis-vaccenic acid was associated with a 41% lower risk of HF with antecedent CHD (95% CI: 17%-59%) in a multivariable adjusted model. CONCLUSIONS: Our data suggest that higher plasma levels of plasma cis-vaccenic acid may be associated with a lower risk of HF with antecedent CHD. Confirmation of these results in the general population including women and other ethnic groups is warranted.